ARCT Stock Plunges 59% in Three Months: Here's What You Need to Know

Core Insights - Arcturus Therapeutics (ARCT) shares have dropped 59.4% over the past three months due to mixed interim results from a mid-stage study of its inhaled mRNA therapy, ARCT-032, for cystic fibrosis (CF) patients [2][6] Study Results - ARCT-032 utilizes a proprietary LUNAR lipid-mediated aerosolized platform to deliver CFTR mRNA to the lungs of CF patients who do not respond to existing treatments [3] - Interim data from the Phase II study showed no significant improvement in Forced Expiratory Volume in 1 second (FEV1) from day 1 to day 28 [4] - A post hoc exploratory analysis indicated modest lung-function gains in four out of six Class-I CF patients, with mean absolute and relative increases of 3.8% and 5.1% in percent predicted FEV1, but these changes are within the expected natural variability [5] - AI-assisted high-resolution computed tomography (HRCT) scans showed reductions in mucus plugs and volume in four of six patients by day 28, suggesting potential efficacy in reducing mucus burden [6] Safety Profile - ARCT-032 demonstrated a favorable safety profile, with treatment-related adverse events similar to those in the Phase I study, and one serious adverse event deemed unrelated to the treatment [8] Future Plans - The third cohort of the Phase II study is currently enrolling up to six patients to assess dose-escalation at 15 mg, with plans for a 12-week study involving up to 20 CF patients in 2026 [9] Market Context - Cystic fibrosis is a serious genetic disease caused by CFTR mutations, leading to severe respiratory complications, and existing CFTR modulators do not benefit all patients, creating a need for alternative treatments [10][11]